NATIVE AQUATIC SHORELINE VEGETATION PROJECT

Project Overview

The primary objective of the project is to introduce additional native aquatic vegetation in the Lake Anna watershed.

The Lake Anna watershed covers more than 218,500 acres (342 square miles) in the rural Piedmont area of central Virginia, comprising the headwaters of the York River. The watershed is in three counties, Louisa, Orange, and Spotsylvania and includes numerous streams and creeks as well as the headwaters of the North Anna River. These creeks, streams, and rivers flow into the northernmost parts of Lake Anna and flow southeast to a dam erected in the late 1960s to impound the North Anna River. The North Anna River flows downstream past the dam until it joins the South Anna River south of the town of Doswell, VA. From that point, the river becomes the Pamunkey River. The Pamunkey River flows south and joins the Mattaponi River at the town of West Point to form the York River. The York River flows into the Chesapeake Bay.

The project is focused on education, outreach and the expansion of existing shoreline vegetation to establish natural nutrient consumers to reduce the amount of phosphorous and nitrogen available to the phytoplankton biomass in Lake Anna. Nutrients are primary food/energy sources for phytoplankton species that naturally occur in freshwater and are known to be primary contributors to the exponential growth of cyanobacteria that results in Harmful Cyanobacteria Blooms (HCBs).

Areas of the upper portions of Lake Anna have been placed under recreational advisories issued by the Virginia Department of Health (VDH) related to cyanobacteria cell counts in each of the past five years (2018-2022). VDH issues these advisories due to the potential health impacts caused by contact with and ingestion of cyanobacteria cells and toxins the cyanobacteria can produce. The cyanobacteria documented by VDH to exist in Lake Anna include species capable of producing hepatotoxins that have negative impacts on human and animal liver functions and neurotoxins that can impact the nervous systems in humans and animals. VDH issues a recreational advisory when either cell counts of potentially toxic cyanobacteria species exceed an established threshold or when toxin levels exceed thresholds established by the Environmental Protection Agency (EPA) for human recreational exposure. Cyanobacteria have adapted to their environment and are capable of exponential population growth in a very short period. This exponential growth results in HCBs and an imbalance in phytoplankton population densities in the lake.

This project works to promote biodiversity in the watershed and lake through a holistic ecological approach involving human interaction with the natural environment to impact the cyanobacteria imbalances present during HCBs. The project is also part of a circular economy involving the agriculture and forestry areas located in the Lake Anna watershed where studies have shown them to be the source of up to 80% of nutrient loading in the lake.  The nutrients produced and released in the watershed eventually make their way into the lake and become available to the plant, animal, and phytoplankton biomass. Increasing the amount of natural vegetation on the shorelines of the streams and creeks in the watershed and along the lake shoreline will reduce these nutrients and provide food and habitat resources for fish, ducks, geese, and other wildlife that inhabit the Lake Anna ecosystem. Finally, this project promotes water stewardship through the improvement of water quality in the areas of the lake where the shoreline vegetation is planted. Anticipated improvements include the lowering of Total Phosphorous (TP) and Total Nitrogen (TN) levels as well as the stabilization of water quality field parameters such as pH and dissolved oxygen. The Lake Anna Civic Association (LACA) monitors water quality parameters including TP, TN, chlorophyll, E. coli, pH, temperature, and dissolved oxygen throughout the year. The water quality improvements are expected to take place over several years, but this project will increase the frequency of this monitoring to measure initial effects from the additional shoreline vegetation. LACA has monitored water quality parameters in the lake for more than 20 years and we will continue to do so into the future so the impacts will be monitored long after the completion of this project.

The project has four main tasks. Task 1, Education & Outreach, is focused on educating the public about the impact that excess nutrients have on the environment with a specific focus on Lake Anna. The education and outreach component of this project will focus on homeowners and landowners in the Lake Anna watershed and on middle and high school students in the three counties surrounding Lake Anna. We will use trained volunteers and coordinate with Master Gardeners, Master Naturalists, staff of local Soil and Water Conservation Districts, and educators from local middle and high schools and college/university professors to educate the public about the need for robust shoreline buffers and submerged aquatic vegetation (SAV) in our watershed. The volunteers for this project include LACA members.  LACA has existing academic relationships and partnerships with Virginia Tech, Randolph-Macon College, Old Dominion University, William & Mary, and the University of Virginia. We will utilize these partnerships to the maximum extent possible to include undergraduate researchers and professors in our project. The educational component of the project will be executed early in 2023 before the spring planting and growing season and our outreach will include the entire Lake Anna watershed, not just the lake itself.

Task 2, Planting of Native, Aquatic Shoreline Vegetation, involves the purchase and planting of native, aquatic plants on 2-3 miles of shoreline in the northern areas of the lake near the confluence of the tributaries with lake waters. The exact location of plantings is dependent on site surveys that will be conducted in the spring when existing vegetation starts its normal annual growing season.

Task 3, Water Quality Monitoring, involves a 1-year expansion of LACA’s legacy Water Quality Monitoring Program (WQMP) to measure effects on water quality parameters in the areas where the plantings executed under Task 2 take place.